The 525-foot steel cofferdam surrounding Smith's Cove reaches completion as Irving Equipment Limited drives the last of 117 interlocking steel sheets some 25 feet into the seabed. Mike Jardine confirms the structure went in without major complications, and the team begins pumping more than 100,000 gallons of seawater from the enclosed area. Rick Lagina, Dave Blankenship, and geophysical engineer John Wonnacott then travel to Rhodes Corner Quarry near Bridgewater, Nova Scotia, to inspect a 50-ton industrial wash plant for sale. Billy Gerhardt demonstrates the machine, which uses a hopper, conveyor belt, grizzly bars, and dual shaker decks with spray nozzles to sort and clean excavated material by size. Rick decides to purchase it, recognizing that the volume of spoils from Smith's Cove far exceeds the team's ability to hand-wash and sift.
Jack Begley, Charles Barkhouse, and Doug Crowell return to the Nova Scotia College of Art and Design in Halifax for a second search of the basement beneath the former Creighton and Marshall bookbindery. Navigating a maze of crawl spaces and cobweb-covered corridors they had not previously explored, they discover a large stone matching the documented description of the 90 Foot Stone: approximately two feet long, 15 inches wide, ten inches thick, close to 200 pounds, flat on two sides with rounded corners, and bearing the carved initials L and N. Captain Henry L. Bowdoin reported seeing these same two initials in 1909 after the stone's original inscription had been worn away by decades of use in bookbinding. The team transports the stone back to Oak Island, where Rick, Marty, Craig Tester, Dave, and Paul Troutman examine it and agree its dimensions check every box from the historical record.
On Lot 24, Alex Lagina, Peter Fornetti, and Gary Drayton metal-detect recently cleared woodland and uncover a ramrod consistent with a Brown Bess musket from the late 1700s, a piece of bone, blue-glazed pottery dating to the early 1700s, and a decorative iron latch. Archaeologist Laird Niven later establishes a grid at the site and recovers a pottery base he dates to 1750 through 1840, likely associated with Samuel Ball, the former slave who settled on Oak Island in 1786 and became one of Nova Scotia's wealthiest men. Laird identifies larger stones at the site as potentially structural and suspects the formation could be a cellar, shaft, or filled-in tunnel, prompting him to apply for additional permits.
Astrophysicist and aerospace engineer Dr. Travis Taylor, who holds degrees in optical sciences, quantum physics, and astronomy, joins the team via video call and later visits the island. After reviewing the Eagle Canada seismic data, he proposes radon gas testing as a method for detecting underground voids, a technique used in planetary exploration. He also presents a theory connecting Freemasonry to the island, identifying a star map hidden in the Hiram Abiff drawing template that aligns the constellation Taurus with specific points on Oak Island and the neighboring Frog and Apple Islands. Marty, Jack, and Gary accompany Travis to three locations indicated on the map and find large boulders at each, including one near the stone triangle on the island's southern shore.
The excitement is tempered when Rick and Craig discover more than 30 leaks in the cofferdam at high tide, with several producing garden-hose-level flows. The discovery threatens to derail the entire Smith's Cove operation before it begins. Alex and Peter apply silicone caulking to the joints from the ocean side at low tide, and Mike Jardine recommends digging an interior perimeter trench to intercept groundwater flowing from the island's upland. The combined measures reduce infiltration to manageable levels, and the team prepares to begin excavating toward the U-shaped structure.
